This invention relates to a dip treating apparatus for carrying out a multiple-step process, in which the objects to be treated have to remain for predetermined periods of time in a number of different treating baths. As typical examples of processes of this kind those for developing or processing photographic films and for etching printed circuit cards may be mentioned, but the range of uses of the apparatus is in no way restricted thereto.
More specifically the invention is concerned with an apparatus of the kind just mentioned comprising in combination a plurality of stations arranged in a row, one after the other, and all being designed to receive at least partially uniform carriers of the objects to be treated, at least two consecutive ones of said stations including containers for treatment baths, and a related series of conveyors, each of which is adapted to transfer one carrier at the time between two adjacent stations only, each such conveyor comprising a slide member reciprocatable by means of a driving mechanism along a vertical guideway arranged to one side of the two stations to be served, said slide member carrying a rocker swingable about a horizontal pivot axis between two operative positions, means being provided for forcibly changing the position of said rocker when the slide member during its reciprocating movement approaches its respective end positions, said rocker including at least one catching means operative to engage the carrier to be transferred, said catching means being arranged to move in the direction between the two stations served by the conveyor when the rocker is forced to change its position.
An apparatus of this general kind is previously known through the French Patent Publication No. 1 273 343 and offers in comparison with most other known dip treating apparatus, e.g. for film processing, many obvious advantages, among which the most prominent one probably is that, in spite of the fact that several carriers with related groups of objects may simultaneously be on their way through the apparatus, there is a possibility in each one of the different stations to select an uninterrupted dwell time for the carriers that is fully independent of the desired dwell time in all the other stations.
However, the structural design of the apparatus disclosed in the French Patent Publication just referred to is disadvantageous from many points of view and, in particular, makes it impossible to locate the bath containers of the apparatus in close relationship, one after and adjacent the other, which on one hand results in a considerable spaced requirement and on the other hand prevents the containers from bracing themselves against each other, whereby they have to be constructed with very strong walls if there is a need for a great container depth and a great container width counted across the direction of feed of the carriers, which is frequently the case in practice. Evidently this is due to the facts that the conveyors of the known apparatus are of such construction that for their proper operation they need a free space between the containers and that the driving mechanisms of the conveyors are bulky and thus require a substantial distance between the stations. In addition, the various driving mechanisms of the known apparatus have to be connected to a common driving motor through a mechanical power transmission system which is very difficult to expand, should there arise a need for increasing the number of stations in the apparatus.